1. Field of the Invention
The present invention relates to a base station of a mobile communication system as a digital cellular system(DCS) and a personal communication service (PCS), and more particularly, to a multi-sector base station apparatus of a mobile communication system to embody a six-sector base station apparatus by using a three-sector base station MODEM.
2. Discussion of Related Art
In general, it is obligated that a mobile communication system complies with a protocol regularized for a call process in the Electronic Industrial Association, and according to that, a terminal searches for a control channel of a base station as a cell site which has the largest signal intensity of a receiving signal, namely, which is nearest to its own position, in its initial state when power is applied to the terminal.
The nearest control channel is searched, then the mobile communication terminal becomes non-traffic mode and receives a message transmitted from the current base station through the selected channel.
At this time, the base station performs a communication service concerned with a general mobile communication work through a communication message with the terminal as the mobile station or a control station, together with the message mentioned above, and in such communicative work execution, a MODEM for use of the base station is used.
That is, data is transmitted and received through this MODEM in a data communication with the mobile station or with the control station.
FIG. 1 provides a block diagram of a conventional three-sector base station apparatus for performing the communication with the mobile station by using this MODEM.
As shown in FIG. 1, the three-sector base station apparatus is constructed by first and second base station MODEMs 1,2 for generating data to be transmitted to the mobile station, e.g., xcex1 sector data, xcex2 sector data and xcex3 sector data, and receiving data transmitted from the mobile station, namely, the xcex1 sector data, the xcex2 sector data and the xcex3 sector data; a base station MODEM output digital combiner 3 for combining signals respectively generated in the first and second base station MODEMs 1,2, and outputting it; an intermediate frequency modulator 4 for modulating transmission data per individual sector into respective intermediate frequency signals, the transmission data being outputted from the base station MODEM output digital combiner 3; a high frequency modulator 5 for modulating intermediate frequency (IF) per each sector, which is gained in the intermediate frequency modulator 4, into each high frequency signal, and after that, outputting the signals to antennae ANT1,ANT2,ANT3 for respective sectors; a high frequency demodulator 6 for demodulating mobile station transmission high frequency(HF) received to the antenna ANT1,ANT2,ANT3 per each sector; and an intermediate frequency demodulator 7 for extracting the IF signals from the HF signals respectively demodulated in the HF demodulator 6 and transferring them to the first and second base station MODEMs 1,2 according to the individual sectors.
Operations of the conventional three-sector base station apparatus with such construction are as follows.
The transmission data outputted from the first and second base station MODEMs 1,2 according to the respective sectors is combined in the base station MODEM output digital combiner 3.
This base station MODEM output digital combiner 3 includes a serial/parallel conversion and output controller, a saturator and a data combiner, though they are not shown in the drawings. The serial/parallel conversion and output controller converts output data of the base station MODEM into parallel data, detects parity error of the converted parallel data and controls an output of each channel card according to its detection result. The saturator eliminates invalid information out of channel data outputted from the serial/parallel conversion and output controller, and passes only valid data. The data combiner selectively adds up the channel data outputted from the saturator according to individual channels and outputs only the valid information in which the invalid information is eliminated from the added channel data, as final output data.
Like this, the transmission data outputted from the base station MODEM output digital combiner 3 is modulated in to the IF per each sector in the IF modulator 4, and is then modulated into the HF per each sector in the HF modulator 5, and after that, is transmitted to the mobile station through the antenna ANT1,ANT2,ANT3.
Meantime, the signal transmitted from the mobile station is received to the antenna ANT1,ANT2,ANT3 per each sector, and is demodulated into an original signal in the HF demodulator 6. Then, the IF is extracted from this demodulated original signal in the IF demodulator 7 and is transferred as an actual reception signal to the first and second base station MODEMs 1, 2.
The conventional base station apparatus with such operations is the base station apparatus for use of three sectors, and in order to use it for use of six-sector base station, conventionally two three-sector base station apparatuses are combined to embody the six-sector base station apparatus, this three-sector base station apparatus being as that shown in FIG. 1.
However, like this, in a case of combining two three-sector base station apparatuses to embody the six-sector base station apparatus, a soft handoff occurs between specific sectors. Thus, two traffic channels should be allotted, which causes a drop in an efficiency of the traffic channel.
Accordingly, the present invention is directed to a multi-sector base station apparatus of a mobile communication system that substantially obviate one or more of the limitations and disadvantages of the related art.
A primary object of the present invention is to provide a multi-sector base station apparatus in a mobile communication system, which is capable of realizing a six-sector base station apparatus by using a three-sector base station MODEM, in order to settle a general problem caused in a six-sector base station apparatus provided by conventionally combining two base station apparatuses for use of three sectors.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure as illustrated in the written description and claims hereof, as well as the appended drawings.
To achieve these and other advantages, and in accordance with the purpose of the present invention as embodied and broadly described, the six-sector base station is embodied by using a base station MODEM for use of three sectors, therefore a softer handoff between sectors occurs and a traffic channel being under a current speech in this softer handoff is allotted to other sector, to thereby heighten an efficiency of the traffic channel.
The inventive base station apparatus based on such technical spirit comprises a peripheral equipment controlling unit for transferring sector conversion control signals outputted from a central processing unit (CPU) for controlling an overall operation of a base station, to peripheral equipments; a sector conversion controlling unit for generating a number of control signals for a sector conversion according to the control signals and sector conversion data gained from the peripheral equipment controlling unit; and a sector converting unit for performing a switching for sectors of transmission signals from the base station MODEM and reception signals transmitted from a mobile station, in response to numerous control signals generated in the sector conversion controlling unit.
The sector converting unit transmits the transmission signals gained from the base station MODEM to six sectors, and receives, through six sectors, reception signals transmitted from the mobile station.
Further, the sector converting unit is composed of a transmitter for converting a three-sector signal outputted from the base station MODEM into a six-sector signal in response to numerous control signals outputted from the sector conversion controlling unit, and a receiver for converting a six-sector reception signal transmitted from the mobile station into a three-sector signal.
In addition, the transmitter is constructed by first through third demultiplexors for converting the three-sector signal outputted from the base station MODEM into the six-sector signal.
The receiver is also constructed by first through third multiplexors for converting the six-sector reception signal transmitted from the mobile station into the three-sector signal.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.